The proposed research will initiate a systematic investigation into the in vitro mechanisms underlying the increase in cellulase specific activity during cellular aging in the slime mold, Dictyostelium discoideum. Current efforts will be directed toward: (1) a purification and characterization of cellulase and the cellulase inhibitor; (2) the elicitation of specific antisera against homogenous preparations of cellulase and the inhibitor; and (3) a quantitation of the levels of cellulase and the inhibitor with their respective antisera during the terminal stages of aging and maturation. An understanding of the mechanisms responsible for the above increase in specific enzyme activity (i.e., alterations in enzyme and/or inhibitor levels) will provide information relevant to the in vivo mechanisms associated not only with the activation of latent enzymes such as cellulase, during germination but also with those cellular processes responsible for the initiation and maintenance of enzyme-specific latency during cellular aging.